Write Java without paying for the IDE in RAM.

Lithe is a lightweight native Java IDE for macOS. It keeps the parts of IntelliJ IDEA you actually use every day, in about 1/5 of the memory.

Download for Free GitHub

Java & Spring Boot · Maven and Gradle · macOS 13+ and Windows

src/main/java›com.example.order›OrderService.javaUTF-84 spacesJava 21

Open a file, search the project, or explore the sidebar.

A Java IDEyou can leaveopen all day.

Browsing code sits at 200–300 MB. A normal working session runs around ≈400 MB, with peaks of 700–800 MB when services are running.

Light enough to forget

Around ≈400 MB in everyday use, so Lithe can stay in the background instead of being closed to free up RAM.

The IDEA core you know

Project structure, editor, search, navigation, and diff. Maven and Gradle projects open as they are.

Ready for AI-written code

When an AI tool edits your files, read the diff in the file it belongs to before you commit.

MEASURED

Three readings from a real workday.

Resident memory on the same Spring service project, taken after indexing completes.

Browsing code 200–300 MB

Project open, reading and navigating.

Everyday work ≈400 MB

Editing, search, diff, running tests.

Peak 700–800 MB

Several services running at once.

How we build Lithe.

An IDE should earn its memory. Everything you are not using should not be running.

Keep the workflow familiar. A lighter tool is not worth relearning.

James Whitaker Backend engineer

Project tree, navigation, and diff sit where I already look. Switching over barely took any relearning, and the memory drop is obvious.
Priya Nair Spring Boot developer

IDEA plus Docker used to fill the machine. I can leave Lithe open all day now, and the fans barely spin.
Daniel Reeves Software engineer

The editor and file tree feel familiar. For day-to-day Spring work I do not need a full IDEA instance sitting in the background.
Aimee Park Independent developer

Search and jump-to-definition are where I expect them. Walking an unfamiliar service is much easier when the IDE stays out of the way.

James Whitaker Backend engineer

Project tree, navigation, and diff sit where I already look. Switching over barely took any relearning, and the memory drop is obvious.
Priya Nair Spring Boot developer

IDEA plus Docker used to fill the machine. I can leave Lithe open all day now, and the fans barely spin.
Daniel Reeves Software engineer

The editor and file tree feel familiar. For day-to-day Spring work I do not need a full IDEA instance sitting in the background.
Aimee Park Independent developer

Search and jump-to-definition are where I expect them. Walking an unfamiliar service is much easier when the IDE stays out of the way.

Marcus Grant Systems engineer

After an AI agent touches several files, the side-by-side diff stays next to the code. I can check the result before committing.
Amir Shah Full-stack engineer

Everyday use sits around 400 MB. Browser, containers, and a local model can finally stay open together.
Hannah Cole Platform engineer

This is the Java IDE I am fine leaving open all day. It is light, but the daily workflow is still there.
Marta Silva Java developer

Existing Maven projects open as they are. I spend less time configuring the editor and more time reading the service.

Marcus Grant Systems engineer

After an AI agent touches several files, the side-by-side diff stays next to the code. I can check the result before committing.
Amir Shah Full-stack engineer

Everyday use sits around 400 MB. Browser, containers, and a local model can finally stay open together.
Hannah Cole Platform engineer

This is the Java IDE I am fine leaving open all day. It is light, but the daily workflow is still there.
Marta Silva Java developer

Existing Maven projects open as they are. I spend less time configuring the editor and more time reading the service.

OPEN SOURCE

Built in the open.

Lithe is shaped in public by 16 people who report, review, and ship the work.

16 contributors

View all contributors

SUPPORTED BY

Built with support from the community.

Lithe is made possible by partners who help keep independent development moving.

FAQ

What is Lithe?

Lithe is a lightweight Java IDE for developers who keep an IDE open all day but do not need a full heavyweight environment. It keeps the IDEA-style workflows you use most — project navigation, editing, search, Maven, run and debug, Git diff — and starts everything else only when you ask for it.

How much memory does it actually use?

Around 200–300 MB once a typical project is open, and roughly ≈400 MB in normal day-to-day use. Running several services at once pushes the peak to 700–800 MB. Actual usage varies with project size and which services you have running.

Is it a replacement for IntelliJ IDEA?

For everyday reading, editing, navigating, running, and reviewing Java code, it is meant to be. For deep refactoring, the full inspection set, and the plugin ecosystem, IDEA is still ahead — that is a deliberate trade, and it is what keeps Lithe small. Many developers keep both and reach for IDEA when they need the heavy tooling.

What does it support?

Java and Spring Boot are the focus, with Maven and Gradle projects opening as they are. Releases bundle the Eclipse JDT Language Server, so there is no separate setup. Entry points are auto-detected for Spring Boot, Java, Maven, Gradle, npm, Cargo, Go, Python, Make, Docker Compose, and shell projects. Java features need JDK 17 or later.

Which platforms are supported?

macOS 13 or later on Apple silicon and Intel, plus Windows x64. On macOS you can also install and update through Homebrew.

Is Lithe open source?

Yes. Lithe is developed in the open under the Apache-2.0 license. You can inspect the source, report issues, and contribute on GitHub.

Where can I report a problem or request a feature?

Open an issue in the Lithe GitHub repository with the steps to reproduce, your OS version, and any useful screenshots or logs.